Variable-capacity liquid motor



w. KUHN VARIABLE CAPACITY LIQUID MOTOR Filed 1. 2 2 Shoets-Shoet 1 July20 192 1,593,498

/n yen for:

July 20 1926.

W. KUHN VARIABLE CAPACITY LIQUID MOTOR 2 Sheets-Sheet 2 Filed March 1.

fllllllul Patented July 20, 1926.

1,593,498 FICE.

WILHELM KU'HN, OF ESCHERSHEIMI, NEAR FRANIGORT-ON-THE-MAIN, GERMANVARIABLE-CAPACITY LIQUI D MOTOR.

Application filed March 1, 1924, Serial No. 696,322, and in Germany June26, 1922.

This invention relates to fluid operated motors or pumps andparticularlyto a rotary motor of the sliding abutment impact type. Such motors, ingeneral, are characterized by the provision of acylindrical rotoroperating in a cylindrical casing, on an axis eccentric to the axis ofsaid casing, the rotor carrying radial abutments which are projectedoutwardly by suitable means into sliding contact with thecircumscribingwall of the casing. The eccentric mounting of the rotor causes theabutments to reciprocate radially, through co-action with saidcircumscribing wall, defining between themselves and said wall chambersof progressively increasing capacity as they approach the point ofgreatest eccentricity, and which progressively diminish in capacity asthey recedebeyond this point. The inlet ofthe motor communicates withthe chambers of increasing capacity, while the outlet communicates withthose chambers which are progressively diminishing.

It is frequently desirable to alterthe capacity of a motor of this type,whether functioning as a motor or pump, this having been attemptedheretofore by varying the eccentricity of the rotor. Great diflioultyhas been experienced, however, in'preserving a seal between the sides ofthe rotor and those of the casing in making this adjustment, so thatvariable capacity motors of this type have been pronounced impractical.

One of the objects of the present invention is to provide a novelconstruction by means of which the relative eccentricity between therotor and easing or cylinder with which it cooperates may be variedwithout any disturbance of the packing.

Another object of the invention is to provide novel means forsimultaneously actuating the sliding abutments to cause themautomatically to accommodate themselves to changes in the relativeeccentricity of the parts with which they coact. Still another object ofthe invention is the provision of a.fluid actuated motor so constructedthat leakage of the-motive fluid, and entry of air, under certainconditions, is prevented.

Other objects of the invention, will appear as the following descriptionof a preferred embodiment of my invention proceeds.

In the drawings, in which similar reference characters are used in theseveral figures to denote the same part,

Fig. 1 is a longitudinal section of a fluidactuated motor embodying myinvention.

Fig. 2 a side view with the side wall removed.

Referring now in detail to the several figures, the numeral 7 representsa shaft upon which the-rotor 2 is keyed. Said shaft is carried inbearings at the opposite sides of a frame, which in the present instancetakes the form of a casing 12, for apurpose which Wlll' presentlyappear. A stationary cylinder 1 is mounted withinthe casing 12, the sameenclosing a cylindrical chamber 1' within which the rotor 2 operates.Said cylinder is provided with side walls 4 and 4 one of which maybeintegral with the cylinder while the other, for example the side wall4, is detachably secured to the cylinder so that it may be removed forthe insertion and assemblage of the rotor parts.

The rotor 2 is formed with radial guideways 2 in which the abutments 3are mounted so as to be freely slidable in a radial direction. Saidabutments are normally maintained with their outer ends close to butslightly' out of contact with the circumscribing wall of the cylindricalchamber 1' thereby avoiding the loss of efiiciency of the motor due tofriction between the abutments and said circumscribing wall. Theabutments 3 are retained in this position by means of trunnions 3projecting from opposite. sides of the abutments extending into annulargrooves 8' formed inthe inner face of the side walls 4. and 4'concentrically with the cylinder axis. In the normal operation of thedevice the cylinder 1 is eccentric with respect to the rotor 2, so thatthe abutments are caused to reciprocate during the revolution of therotor, being guided by the grooves 8.

The cylinder is'provided, preferably in the direction of its axis ofeccentricity with upper and lower slides 10 and 11, the latter beingsupported by the casing 12, said slides, and with them the cylinder 1,being slidable relative to said casing and to the shaft 7 in thedirection of said axis of eccentricity when the slides are actuated bysuitable means such as the screw 10. By this means, the degree ofeccentricity of, the cylinder relative to the rotor may be altered,varyin the capacityof the motor. The inlet an outlet passages to andfrom the rotor, may, for convenience pass through the lower slide 11,the walls of said passages assuming telescopic relation with respect toinlet and outlet pipes 15 carried by the slide 11 at the base of themotor.

In order that the cylinder 1 may be translatorily moved with respect tothe rotor without disturbing the packing between the cylinder and rotorI have provided flanged packing collars 5 and 5' journalled upon theshaft 7 and making sealing contact with the opposite sides of the rotor2. The sidewalls 4 and 4 are provided with apertures 18' surrounding theshaft 7 of such size as to give ample clearance for the cylinder 1 to bemoved in a direction transversely of the shaft throughout the range ofeccentric movement for which it' is designed. The packing collars 5 and5 are preferably formed in a stepped manner comprising a pair of annularshoulders 16' and an intermediate cylindrical sealing surface 17 Theouter ends of the packing collars are provided with flanged nuts 6 whichmay be screwed inwardly to adjust the degree of compression of theshoulders 16 of the flanged packing collars 5 and 5' against the innersides of the side walls 4 and 4. When it is desired to adjust theeccentricity of the cylinder the screw 10 is turned to impart the properdegree of translatory movement to the cylinder. This may be done withoutany disturbance whatsoever of the sealing surfaces between the packingcollars and rotor.

It will be noted from Figure 1 that the provision of the steppedelongated sealing surfaces between the packing collars and r0- tc-r hasnecessitated a considerable cutting away of the material at the ends ofthe hub of the rotor, so that the ends of the guideways 2 in which theabutments 3 slide are abnormally short. This is compensated for byreducing the thickness of the middle portion of the hub of the rotor inthe planes of said guideways, making the bases of the guideways concaveas is indicated at 20 and providing the abutments with basal extensions19' fitting into the concave portions of the guideways.

It will be readily understood from an inspection of Figure 2 that, sincethe position of the abutments is determinedby the'guiding grooves 8(which are concentric to the cylinder) and not by springs as employed inother constructions to force the abutments outwardly, there is nothinginherent in the construction of the abutments or the circumscribing wallof the cylinder to cause the abutments to alter their position tocorrespond with new positions of said circumscribing wall when thecylinder is translatorily moved in the act of changing the degree ofeccentricity thereof. Special means are therefore provided for causingthe abutments to act together in changing their corelative position tocorrespond with that of the circumscribing cylinder wall, said meansconsisting of a chain of abutting guiding blocks 8 movingin the grooves8 and between certain of which the trunnions 3 of the abutments areintercalated. The blocks 8 are held by rings 9 at the fitting up of thedrive-mechanism.

As will be seen on referring to these figures the rings 9 abut withtheir outer circumference against the bottom of the grooves provided forthe purpose on the sliding blocks. The sliding blocks are thus held bythe rings in such a manner, that they always take up a definite positionin relation to the ring and therefore to the cylinder. The outerdiameters of the rings 9 are so large that they project into slotsformed in the guide trunnions of the abutments 3, whereby a lateralstripping off of the sliding blocks from the pistons is renderedimpossible, as long as the rotor with She pistons is entirely or partlyin the cylin- In the preferred construction of my motor the frameconstitutes a casing 12 which surrounds the cylinder 1 in spacedrelation thereto, forming a chamber 21. This chamber is adapted to befilled with fluid, particularly liquid of the same kind which isutilized as the motive agent. A filler plug 13 is provided, closing anaperture in which liquid may be poured until the chamber 21 has beenfilled. The filler plug may then be replaced, the liquid within saidchamber acting as a sealing means to prevent leakage of motive fluidpast the bearings of the packing collars and also to prevent entry ofair into the motor when it is idle.

' It will be readily understood that I do not limit myself to the exactdetails of construction described and illustrated and that modificationswithin the ambit of my claims will suggest themselves to persons skilledin the art without departing from the spirit of my invention orsacrificing any of its advantages.

What I claim is:

1. In a variable capacity rotary motor, a shaft, a rotor on said shaft,a cylinder enclosing said rotor having side walls through which saidshaft passes and a circumscribing wall defining motive fluid spacebetween said rotor and cylinder, means for moving said cylinderdiametrically of said rotor to alter the degree of eccentricity of saidcircumscribing wall, said side walls being formed with openingssurrounding said shaft and suificiently larger than the shaft to providefor the required range of translatory movement of said cylinder, packingcollars on said shaft making a sliding sealed joint with said rotor,said collars engaging the portions of said side walls adjacent saidopenings and being sufliciently large to close said openings in allpositions of said cylinder, and means for clamping said collars to theside walls of said cylinder.

2. In a variable capacity rotary motor, a shaft, a rotor on said shaft,a cylinder enclosing said rotor having side .walls through which saidshaft passes and a circumscribing wall defining motive fluid spacebetween said rotor and cylinder, said rotor being formed with radialguideways, sliding abutments in said guideways intersecting said motivefluid space, means for moving said cylinder diametrically of said rotorto alter the degree of eccentricity of said circumscribing wall, saidside walls being formed with openings surrounding said shaft andsufliciently larger than the shaft to provide for the required range oftranslatory movement of said cylinder, packing collars on said shafthaving inner faces projecting into and co-acting wth correspondinglyshaped recesses in the sides of said rotor making a sealed jointtherewith, said collars engaging portions of said side walls adjacentsaid openings and being sufficiently large to close said openings in allpositions of said cylinder, means for clamping said collars to the sidesof said cylinder, said guideways being relatively shallow adjacent saidrecesses and relatively deep adjacent the intermediate portions of therotor, and said abutments being correspondingly proportioned.

3. In a variable capacity rotary motor, a shaft, a rotor on said shaft,a cylinder enclosing said rotor having side walls through which saidshaft passes and a circumscribing wall defining motive fluid spacebetween said rotor and cylinder, means for moviiig said cylinderdiametrically of said rotor to alter the degree of eccentricity of saidcircumscribing wall, said side walls being formed with openingssurrounding said shaft and sufficiently larger than the shaft to providefor the required range of translatory movement of said cylinder, packingcollars on said shaft making a sliding sealed joint within said rotor,said collars engaging the portions of said side walls adjacent saidopenings and being sufficiently large to close said openings in allpositions of said cylinder, means for clamping said collars to the sidewalls of said cylinder, and a casing surrounding iiaid cylinder adaptedto be filled with iqui 4. In a variable capacity rotary motor, a

shaft, a rotor on said shaft, a cylinder enclosing said rotor havingside walls through which said shaft passes and a circumscribing walldefining motive 'fiuid space between said rotor and cylinder, means formoving said cylinder diametrically of said rotor to alter the degree ofeccentricity of said circumscribing wall, said side walls being formedwith openings surrounding said shaft and siifiiciently larger than theshaft to provide for the required range of translatory movement of saidcylinder, packing collars on said shaft making a sliding sealed jointwith said rotor, said collars engaging the portions of said side walladjacent said openings and being sufliciently large to close saidopenings in all positions of said cylinder, and means for clamping saidcollars to the side Walls of said cylinder, said rotor being formed withradial guideways, and sliding abutments carried in said guideways havingtrunnions projecting from, their sides, the side Walls of said cylinderbeing formed with grooves receiving said trunnions, said grooves beingconcentric to said circumscribing Wall.

5. In a variable capacity rotary motor, a shaft, a rotor on said shaft,a cylinder enclosing said rotor having side walls through which saidshaft passes and a circumscribing wall defining motive fluid spacebetween said rotor and cylinder, means for moving said cylinderdiametrically of said rotor to alter the degree of eccentricity of saidcircumscribing wall, said .side walls being formed with openingssurrounding said shaft and sufliciently larger than the shaft to providefor the required range of translatory movement of said cylinder; packingcollars on said shaftmaking a sliding sealed joint with said rotor, sailcollars engaging the portions of said side wall adjacent said openingsand being sufliciently large to close said openings'inall positions ofsaid cylinder, means for clamping said collars to the side walls of saidcylinder, said rotor being formed with radial guideways, slidingabutments carried in said guideways having trunnions projecting fromtheir sides, the side walls of said cylinder being formed with groovesreceiving said trunnions, said grooves being concentric to saidcircumscribing wall, and means for causing said abutments to alter theirpositions to correspond to changes in the degreeof eccentricity of saidcircumscribing wall, said means comprising a chain of abutting blockstravelling in said grooves between certain of which said trunnions areintercalated;

6. In a variable capacity rotary motor, a shaft, a rotor on said shaft,a cylinder enclosing said rotor having side walls through which saidshaft passes and a circumscribing wall defining motive fluid spacebetweensaid rotor and cylinder, means for moving said cylinderdiametrically of said rotor to alter the degree of eccentricity of saidcircumscribing wall, said side walls being formed with openingssurrounding said shaft and sufficiently larger than the shaft to providefor the required range of translatory movement of'said cylinder, packingcollars on said shaft making a sliding sealed joint with said rotor,said collars. engaging the portions'of said side wall adjacent saidopenings and being sufficiently large to close said openings in allpositions of said cylinder,

means for clamping said collars to the side walls of said cylinder, saidrotor being formed with radial guideways, sliding abutments carried insaid guideways having trunnions projecting from their sides, the sidewalls of said cylinder being formed with grooves receiving saidtrunnions, said grooves receiving said trunnions and being concentric tosaid circumscribing wall, means for causing said abutments to altertheir positions to correspond to changes in the degree of eccentricityof said circumscribing wall, said means comprising a chain of abuttingblocks travelling in said grooves between certain of which saidtrunnions are intercalated, and rings engaging grooves in said trunnionsand blocks for holding them together.

In testimony whereof I have afiixed my signature.

WILHELM KUI-IN.

